Risk factors for keratoconus progression after treatment by accelerated cross-linking (A-CXL): A prospective 24-month study

PURPOSE

Identification of potential predictive factors for keratoconus progression after treatment by accelerated Cross-linking (A-CXL) SECONDARY OBJECTIVES: Evaluation of clinical and topographic outcomes for two years following accelerated cross-linking treatment for progressive keratoconus including: best spectacle corrected visual acuity (BSCVA), thinnest pachymetry, maximum keratometry (Kmax), cylinder.

STUDY

Prospective, interventional, monocentric study. SITE: Metz-Thionville Regional Medical Center, Lorraine University, Mercy Hospital, Metz, France.

PATIENTS AND METHODS

We included 82 eyes of 60 patients between March 2014 and June 2016 who underwent accelerated corneal cross-linking (A-CXL) with epithelial debridement for progressive keratoconus, with a minimum follow-up of 2 years. A complete clinical evaluation and corneal topography were performed before cross-linking, and subsequently at 6, 12 and 24 months post-procedure. The following parameters were monitored during follow-up: best spectacle corrected visual acuity (BSCVA), minimal pachymetry, maximum keratometry (Kmax), mean anterior and posterior curvatures, maximum posterior curvature, presence of optical aberrations, subdivided into spherical aberration, coma, astigmatism, higher order optical aberrations and residual optical aberrations. After a 2-year follow-up, two groups, defined as "responders" and "non-responders" to treatment, were separated for analysis, and their initial characteristics were compared.

RESULTS

Data for 82 eyes of 60 patients with progressive keratoconus with a mean age of 24±7 years were studied. Fourteen eyes (17.1%) showed signs of progression after treatment by A-CXL (non-responders), and 68 eyes (82.9%) showed stabilization of the disease (responders). Characteristics of non-responding eyes after A-CXL included a younger mean age (20±5 vs. 25±7 years) (P=0.04) and a lower initial mean BCVA for non-responders of 0.44±0.16 logMAR vs. 0.29±0.19 logMAR (P=0.03). Non-responders also had a higher mean maximal posterior curvature (AKB) of -10.84±1.72D vs. -9.46± 1.12D (P=0.03). They also showed more higher order optical aberrations (3.84±1.72D vs. 2.4±1.02D; P=0.01), including coma (3.85±1.81D vs. 2.1±1.01D; P=0.03) and more residual aberrations than responders (1.05±0.44D vs. 0.45±0.6D; P=0.005). No significant differences were found between responders and non-responders for the other parameters in our study.

CONCLUSION

Eyes with progressive keratoconus who did not respond to A-CXL treatment were the most aggressive cases in the youngest patients, with highest maximum corneal curvatures and most pronounced optical aberrations. These patients should be informed in advance of the high risk of non-response to A-CXL treatment, and of the potential need for additional treatment in the future.

Lateral tarsal strip versus lateral tarsal strip with three-snip punctoplasty for managing epiphora in involutional ectropion

PURPOSE

To compare the efficacy of two surgical techniques-lateral tarsal strip (canthoplasty) alone, and lateral tarsal strip with three-snip punctoplasty-in reducing epiphora arising from involutional ectropion with partial punctal stenosis.

METHODS

Fourty patients with involutional ectropion and partial stenosis of the lacrimal punctum were randomly allocated to two treatment groups. Group 1 patients received lateral tarsal strip alone with only non-invasive stenting of the punctum, and group 2 patients received tarsal strip plus three-snip punctoplasty. Subjective assessment of epiphora was achieved via completion of a quality of life (QoL) questionnaire preoperatively and at postoperative month 3. Eyelid position, adverse outcomes and corneal dryness (via Oxford grading scheme) were also assessed postoperatively. Only patients with unilateral problems were included in the study.

RESULTS

Forty eyes of 40 patients were included: 20 in each group. The mean ages of group 1 and group 2 patients were 79±11 and 80±9 years, respectively. All patients reported significantly reduced eye watering after surgery, with no significant intergroup difference in subjective outcomes, except that computer usage and night driving (P<0.05), improved in a more significant way in group 2. Eyelid malposition was corrected in all cases, there were no cases of postoperative punctal eversion, and no significant adverse events or complications occurred. Finally, the mean improvements in the dryness/keratitis score (using the Oxford scheme) were comparable between the 2 groups (P=0.34).

CONCLUSION

The study findings indicate that treatment of involutional ectropion with partial punctal stenosis by lateral tarsal strip with three snip punctoplasty does not provide greater reduction in discomfort secondary to epiphora than conventional lateral tarsal strip alone, except for specific situations such as night driving or computer use.